Articles & Issues
- Language
- korean
- Conflict of Interest
- In relation to this article, we declare that there is no conflict of interest.
- Publication history
-
Received May 9, 2017
Accepted July 1, 2017
-
This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits
unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright © KIChE. All rights reserved.
All issues
수소불화탄소 및 수소염화불화탄소 냉매(R-134a, R-227ea, R-236fa, R-141b)를 이용한 가스 하이드레이트 형성에 관한 계산화학적 해석
Computational Chemistry Study on Gas Hydrate Formation Using HFC & HCFC Refrigerants (R-134a, R-227ea, R-236fa, R-141b)
국립부경대학교 화학공학과, 48547 부산광역시 남구 신선로 365 1국립부경대학교 환경공학과, 48513 부산광역시 남구 용소로 45
Department of Chemical Engineering, Pukyong National University, 365, Sinseon-ro, Nam-gu, Busan, 48547, Korea 1Department of Environmental Engineering, Pukyong National University, 45, Yongso-ro, Nam-gu, Busan, 48513, Korea
Korean Chemical Engineering Research, October 2017, 55(5), 704-710(7), 10.9713/kcer.2017.55.5.704 Epub 19 October 2017
Download PDF
Abstract
가스 하이드레이트 형성원리를 이용한 해수담수화는 이미 상용화된 역삼투 방식에 비하여 아직 실증화 단계이지만 그 공정이 비교적 단순하고 특히 냉매를 객체가스로 사용할 경우 아주 낮은 공정 온도가 필요하지 않아 에너지 소비량(thermal budget)이 향상될 가능성이 있기 때문에 여전히 많은 관심을 받고 있다. 따라서 본 연구에서는 수소불화탄소(HFC, hydrofluorocarbon) 및 수소염화불화탄소(HCFC, hydrochlorofluorocarbon) 계열의 냉매들을 객체가스로 한 가스 하이드레이트형성 거동을 에너지적인 관점에서 해석하고자 하였고 이를 위해 밀도 범함수(DFT, density functional method) 이론을 기반으로 한 분자모델링을 도입하였다. 객체가스(guest gas)로 R-134a, R-227ea, R-236fa, R-141b를 선정하였으며 계산을 위하여 물 분자로 이루어진 512, 51262, 51264의 세 가지 구조의 동공들(cavities)을 구성하였다. 동공, 객체가스, 그리고 객체가스가 삽입된 동공의 구조를 분자모델링을 이용하여 각각 최적화하였고 계산된 각 구조의 에너지로부터 동공과 객체가스의 결합에너지(binding energy)를 계산하였다. 마지막으로 결합에너지를 비교함으로써 어느 냉매가 가장 유리한 조건에서 가스 하이드레이트를 형성할 지를 판단하였다. 결과적으로 R-236fa가 가장 자발적(spontaneous)으로 가스 하이드레이트를 형성 할 것으로 예상되었고 사람에 대한 낮은 독성과 물에 대한 작은 용해도 측면에서도 가장 적절한 선택으로 평가되었다.
Although the desalination technique using gas hydrate formation is at a development stage compared to the commercially well-established reverse osmosis (RO), it still draws attention because of its simplicity and moderate operational conditions especially when using refrigerants for guest gases. In this study, DFT (density functional theory)-based molecular modeling was employed to explain the energetics of the gas hydrate formation using HFC (hydrofluorocarbon) and HCFC (hydrochlorofluorocarbon) refrigerants. For guest gases, R-134a, R-227ea, R-236fa, and R-141b were selected and three cavity structures (512, 51262, and 51264) composed of water molecules were constructed. The geometries of guest gas, cavity, and cavity encapsulating guest gas were optimized by molecular modeling respectively and their located energies were then used for the calculation of binding energy between the guest gas and cavity. Finally, the comparison of binding energies was used to propose which refrigerant is more favorable for the gas hydrate formation energetically. In conclusion, R-236fa was the best choice in terms of thermodynamic spontaneity, less toxicity, and low solubility in water.
Keywords
References
El-Dessouky HT, Ettouney HM, “Fundamentals of Salt Water Desalination,” Elsevier(2002).
Morris RM, Desalination, 93, 57 (1993)
Ophir A, Gendel A, Kronenberg G, Desal. Water. Reuse., 4, 28 (1994)
Shaban HI, Sep. Purif. Methods, 19, 121 (1990)
Khawaji AD, Kutubkhanah IK, Wie JM, Desalination, 221(1-3), 47 (2008)
Lee KP, Arnot TC, Mattia D, J. Membr. Sci., 370(1-2), 1 (2011)
서유택, 강성필, 이재구, 이흔, NICE, 26(3), 324 (2008)
McCormack RA, Andersen RK, Water Treatment Engineering and Research Group(1995).
Park KN, Hong SY, Lee JW, Kang KC, Lee YC, Ha MG, Lee JD, Desalination, 274(1), 91 (2011)
Ryu H, Kim M, Lim JH, Kim JH, Lee JD, Kim S, J. Korean Soc. Water Wastewater, 30(4), 459 (2016)
Jeffrey GA, J. Incl. Phenom. Macrocycl. Chem., 1(3), 211 (1984)
Sloan ED, “Clathrate Hydrates of Natural Gases,” 2nd ed., Marcel Dekker(1998).
Sloan ED, Energy Fuels, 12(2), 191 (1998)
Sloan ED, Nature, 426, 353 (2003)
Mao WL, Mao H, Goncharov AF, Struzhkin VV, Guo Q, Hu J, Shu J, Hemley RJ, Somayazulu M, Zhao Y, Science, 297(5590), 2247 (2002)
Sloan ED, Am. Mineral, 89(8-9), 1155 (2004)
VonStackelberg M, Muller HR, Z. Elektrochem., 58(1), 25 (1954)
Tillner-Roth R, Baehr HD, J. Phys. Chem. Ref Data, 23(5), 657 (1994)
Liang D, Wang R, Guo K, Fan S, J. Therm. Sci., 10(1), 64 (2001)
Liang DQ, Guo KH, Wang RH, Fan SS, Fluid Phase Equilib., 187-188, 61 (2001)
Ogawaa T, Itoa T, Watanabea K, Taharab K, Hiraokab R, Ochiaib J, Ohmurac R, Morid, YH, Appl. Therm. Eng., 26, 2157 (2006)
Wang X, Dennis M, Hou L, Renew. Sust. Energ. Rev., 36, 34 (2014)
Lim JH, Lee JD, Park SS, Eom KH, Won YS, Clean Technol., 19(4), 476 (2013)
Calm JM, Air-Conditioning and Refrigeration Technology Institute, Arlington, VA(2000).
Johanna L, Kim AR, Jeong G, Lee JK, Lee TY, Lim JH, Won YS, Korean J. Mater. Res., 26(7), 382 (2016)
Karamoddin M, Varaminian F, Desalin. Water Treat., 52, 2450 (2013)
Valtz A, Coquelet C, Baba-Ahmed A, Richon D, Fluid Phase Equilib., 207(1-2), 53 (2003)
Gaussian 09, Revision C.01, Frisch MJ, Trucks GW,... Gaussian, Inc., Wallingford CT(2016).
GaussView, Version 6, Dennington R, Keith TA, Millam JM, Semichem Inc., Shawnee Mission, KS(2016).
Becke AD, J. Chem. Phys., 98, 1372 (1993)
Stephens PJ, Devlin FJ, Chabalowski CF, Frisch MJ, J. Phys. Chem., 98(45), 11623 (1994)
Morris RM, Desalination, 93, 57 (1993)
Ophir A, Gendel A, Kronenberg G, Desal. Water. Reuse., 4, 28 (1994)
Shaban HI, Sep. Purif. Methods, 19, 121 (1990)
Khawaji AD, Kutubkhanah IK, Wie JM, Desalination, 221(1-3), 47 (2008)
Lee KP, Arnot TC, Mattia D, J. Membr. Sci., 370(1-2), 1 (2011)
서유택, 강성필, 이재구, 이흔, NICE, 26(3), 324 (2008)
McCormack RA, Andersen RK, Water Treatment Engineering and Research Group(1995).
Park KN, Hong SY, Lee JW, Kang KC, Lee YC, Ha MG, Lee JD, Desalination, 274(1), 91 (2011)
Ryu H, Kim M, Lim JH, Kim JH, Lee JD, Kim S, J. Korean Soc. Water Wastewater, 30(4), 459 (2016)
Jeffrey GA, J. Incl. Phenom. Macrocycl. Chem., 1(3), 211 (1984)
Sloan ED, “Clathrate Hydrates of Natural Gases,” 2nd ed., Marcel Dekker(1998).
Sloan ED, Energy Fuels, 12(2), 191 (1998)
Sloan ED, Nature, 426, 353 (2003)
Mao WL, Mao H, Goncharov AF, Struzhkin VV, Guo Q, Hu J, Shu J, Hemley RJ, Somayazulu M, Zhao Y, Science, 297(5590), 2247 (2002)
Sloan ED, Am. Mineral, 89(8-9), 1155 (2004)
VonStackelberg M, Muller HR, Z. Elektrochem., 58(1), 25 (1954)
Tillner-Roth R, Baehr HD, J. Phys. Chem. Ref Data, 23(5), 657 (1994)
Liang D, Wang R, Guo K, Fan S, J. Therm. Sci., 10(1), 64 (2001)
Liang DQ, Guo KH, Wang RH, Fan SS, Fluid Phase Equilib., 187-188, 61 (2001)
Ogawaa T, Itoa T, Watanabea K, Taharab K, Hiraokab R, Ochiaib J, Ohmurac R, Morid, YH, Appl. Therm. Eng., 26, 2157 (2006)
Wang X, Dennis M, Hou L, Renew. Sust. Energ. Rev., 36, 34 (2014)
Lim JH, Lee JD, Park SS, Eom KH, Won YS, Clean Technol., 19(4), 476 (2013)
Calm JM, Air-Conditioning and Refrigeration Technology Institute, Arlington, VA(2000).
Johanna L, Kim AR, Jeong G, Lee JK, Lee TY, Lim JH, Won YS, Korean J. Mater. Res., 26(7), 382 (2016)
Karamoddin M, Varaminian F, Desalin. Water Treat., 52, 2450 (2013)
Valtz A, Coquelet C, Baba-Ahmed A, Richon D, Fluid Phase Equilib., 207(1-2), 53 (2003)
Gaussian 09, Revision C.01, Frisch MJ, Trucks GW,... Gaussian, Inc., Wallingford CT(2016).
GaussView, Version 6, Dennington R, Keith TA, Millam JM, Semichem Inc., Shawnee Mission, KS(2016).
Becke AD, J. Chem. Phys., 98, 1372 (1993)
Stephens PJ, Devlin FJ, Chabalowski CF, Frisch MJ, J. Phys. Chem., 98(45), 11623 (1994)
